Acoustic telephone



(No Model.)

B. N. BOTTS.

ACOUSTIC TELEPHONE. No. 286,680. Patented Oct. 16, 1883.

I w WW.

Nv PETERS. Wale-Lithography. Wmhiugwn. D, c.

UNITED STATES PATENT OFFICE.

BARNET N. BOTTS, OF PASO ROBLES, CALIFORNIA.

ACOUSTIC TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 286,680, dated October16, 1883 Application filed March 31, 1883.

To aZZ whom it may concern.-

Be it known that I, BARNET N. Borrs, of Paso Robles, San Luis Obispocounty, State of California, have invented an Improved AcousticTelephone; and ,I do hereby declare the following to be a full, clear,and exact description thereof.

My invention relates to certain new and useful improvements in acoustictelephones.

These improvements consist in the construction of the diaphragm ofeither a transmitter or a receiver and a funnel -shaped mouthpiece inconnection with said diaphragm, whereby it is rendered operative.

The object of my invention is to furnish a simple and effectivetelephone, which obj eet I attain in the following manner, referencebeing made to the accompanying drawings, in whieh Figure l is a verticalsection of my device. Fig. 2 is a view of the diaphragm.

A represents a shallow casing, between the sides of which is clamped, inthe usual manner,a diaphragm, B. This diaphragm (which is plainly seenin Fig. 2) is constructed of thin metal, so cut away as to leave nothingbut a small central hub or surface, a, and a rim, 2), the two beingconnected by radial arms 0.

Into the face of the casing A is let the mouthpiece O, of funnel shape,as shown. The inner opening of the mouth-piece has about an equaldiameter as the central surface, a, of the diaphragm, and is inimmediate relation therewith. With the back of the center of thediaphragm is connected the wire w, which passes out of the casing, andis connected as will here inafter be explained. Asolid plate, which isgenerally used, cannot be affected as readily nor to the same degree asthis light open diaphragm. The inertia of the air must be overcome, andits resistance materially impedes vibration. Therefore by having a smallsur face, as the center a, it does not meet with as (No model.)

much resistance, and if the same power be applied its vibrations will bestronger than if it were a solid plate. In order to concentrate thesound-waves produced by the voice directly upon this small vibratorysurface, the mouth-piece is made of shape shown and described. By theuse of this highly-sensitive diaphragm, none of the energy of the voiceis lost, and therefore it can be transmitted to a greater distance andwith more volume than if it were first resisted by a less delicatetransmitter. This diaphragm is equally serviceable as a receiver, andits utility is not confined alone to acoustic telephones, (for which,however, it is specially adapted;) but it may be used in electrictelephones as well.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a telephone apparatus, a diaphragm having a small central surfaceto receive the vibrations, an outer rim, by which it is clamped, andlight open-work intervening to secure the center to rim, substantiallyas and for the purpose herein described.

2. In a telephone apparatus,the diaphragm 13, consisting of a smallcenter, a, the rim 1), and the radial arms 0, substantially as and forthe purpose herein described.

3. In a telephone apparatus, the diaphragm 13, having the small centera, the rim 1), and the radial arms 0, in combination with thefunnel-shaped month-piece 0, arranged to concentrate the sound-waves onthe small center a, substantially as and for the purpose hereindescribed.

In witness whereof I have hereunto set my hand.

BARNET N. BOTTS.

"Witnesses 1?. H. DUNN,

' VIRGIL SMITH.

